Kenya Wildlife Service and Save The Elephants staff push an elephant as they undertake the collaring of ten elephants ranging near the Standard Gauge Railway to fit them with advanced satellite radio tracking collars in Tsavo National Park, Kenya March 15, 2016. (Photo by Goran Tomasevic/Reuters)

A man holds a cow at the cattle market in Maiduguri, Nigeria, March 9, 2016. A Nigerian government push to strangle the Boko Haram insurgency has shut down the cattle trade that sustained the city of Maiduguri, leaving many residents with no livelihood, including many of the two million people displaced by the war. In recent months the army has taken back much of the territory lost to the jihadists during the five-year insurgency. (Photo by Afolabi Sotunde/Reuters)

These sand-swept images show the ghostly remains of what was once a mineral-rich mining community. In its heyday, the town of Kolmanskop, Namibia, was home to about 700 families. Now all that remains are empty homes filled with sand, while cast-off items such as bathtubs are scattered about the surrounding area. Over time, the sand of the stunning dunes that encircle the town of Kolmanskop has been blown towards the abandoned residences, coating everything from streets to the interiors of houses and workshops. Here: Kolmankop, an abandoned mining town in Namibia. (Photo by David Ogden/Caters News)

A boy sits in a canoe in front of a shed built on a raft in the Makoko fishing community on the Lagos Lagoon, Nigeria February 29, 2016. In Makoko, a sprawling slum of Nigeria's megacity Lagos, a floating school capable of holding up to a hundred pupils has since November brought free education to the waterways known as the Venice of Lagos. It offers the chance of social mobility for youngsters who, like most of the city's 21 million inhabitants, lack a reliable electricity and water supply and whose water-based way of life is threatened by climate change as well as rapid urbanisation. (Photo by Akintunde Akinleye/Reuters)

Indigenous Sahrawi girls play on an improvised see-saw at a refugee camp of Boudjdour in Tindouf, southern Algeria March 3, 2016. UN Secretary General Ban Ki-moon is scheduled to visit the Sahrawi refugees in south-west Algeria's Tindouf region. (Photo by Zohra Bensemra/Reuters)

A woman collects water from a stream outside the village of Tsemera in Ethiopia's northern Amhara region, February 13, 2016. (Photo by Katy Migiro/Reuters)

A women sell food under the wing of a plane wreckage being used as housing in M'Poko Internally Displaced Persons camp in Bangui, Central African Republic on Saturday, February 13, 2016. The M'Poko IDP camp, just outside the capitol's airport, currently houses close to 20,000 people displaced due to the ongoing conflict in Central African Republic. (Photo by Jane Hahn/The Washington Post)

Eritrean refugee children play at Mai-Aini refugee camp near the Eritrean boarder in the Tigrai region in Ethiopia February 10, 2016. Each month as many as 5,000 people flee Eritrea according to U.N. figures, estimates the Eritrean government disputes. The government puts the population at about 3.6 million, while other estimates suggest it could be almost double that. (Photo by Tiksa Negeri/Reuters)